More particularly, the invention relates to a heating and ventilating apparatus of the type comprising a casing which defines a fresh air inlet, a mixing zone in communication with a deicing duct, a ventilating duct, and a heating duct, and means for supplying the mixing zone selectively with cold or heated air. The apparatus further includes at least one fresh air passage member having an inlet port which is in communication with the fresh air inlet, and an outlet port which is open into an outlet chamber in communication with the mixing zone, the outlet chamber supplying the ventilating duct and the heating duct.
A heating and ventilating apparatus of this type is known from Applicants' French patent application No. 95 07424.
In addition, in this known device, the fresh air passage member is mounted for pivoting movement in the casing between a first extreme position and a second extreme position, in such a way that the outlet port of the passage member is directed towards a duct selected from the deicing duct, the ventilating duct and the heating duct.
In this known device, the mixing zone receives air at an adjustable temperature, which is then passed towards the above mentioned ducts, that is to say the deicing duct, the ventilating duct and the heating duct.
The deicing duct is arranged to pass a flow of air towards at least one vent directed towards at least one of the glasses of the vehicle, in particular the windshield. The ventilating duct is arranged to direct a flow of air towards the heads of the occupants, through ventilating vents which are provided on the fascia of the vehicle. Finally, the heating duct, otherwise called a "foot heating duct", is arranged to pass a stream of air towards the feet of the occupants, through at least one vent that exhausts into the lower part of the cabin.
In the apparatus which is known from French patent application No. 95 07424, actuating means are arranged to control the pivoting movement of the fresh air passage member between its two extreme positions.
In this way it is possible to direct the stream of fresh air leaving the outlet port of the fresh air passage member selectively, either towards the deicing duct, the ventilating duct, or the heating duct, depending on the aerodynamic and thermal configuration required by the user.
The selected duct is then supplied with a stream of fresh air from the fresh air passage duct, which mixes with the mixed air derived from the mixing zone, and this enables a stream of air at an intermediate temperature to be obtained.
However, it has been found that the fresh air passage member, in accordance, with the above mentioned French patent application has a tendency to channel the fresh air stream, which does not enable optimum mixing of the fresh air stream and the mixed air stream to be obtained.